<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - materials - alpha hash</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>
		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.module.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three';

			import Stats from 'three/addons/libs/stats.module.js';
			import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
			import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
			import { RoomEnvironment } from 'three/addons/environments/RoomEnvironment.js';

			import { EffectComposer } from 'three/addons/postprocessing/EffectComposer.js';
			import { RenderPass } from 'three/addons/postprocessing/RenderPass.js';
			import { TAARenderPass } from 'three/addons/postprocessing/TAARenderPass.js';
			import { OutputPass } from 'three/addons/postprocessing/OutputPass.js';

			let camera, scene, renderer, controls, stats, mesh, material;

			let composer, renderPass, taaRenderPass, outputPass;

			let needsUpdate = false;

			const amount = parseInt( window.location.search.slice( 1 ) ) || 3;
			const count = Math.pow( amount, 3 );

			const color = new THREE.Color();

			const params = {
				alpha: 0.5,
				alphaHash: true,
				taa: true,
				sampleLevel: 2,
			};

			init();

			function init() {

				camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 100 );
				camera.position.set( amount, amount, amount );
				camera.lookAt( 0, 0, 0 );

				scene = new THREE.Scene();

				const geometry = new THREE.IcosahedronGeometry( 0.5, 3 );

				material = new THREE.MeshStandardMaterial( {
					color: 0xffffff,
					alphaHash: params.alphaHash,
					opacity: params.alpha
				} );

				mesh = new THREE.InstancedMesh( geometry, material, count );

				let i = 0;
				const offset = ( amount - 1 ) / 2;

				const matrix = new THREE.Matrix4();

				for ( let x = 0; x < amount; x ++ ) {

					for ( let y = 0; y < amount; y ++ ) {

						for ( let z = 0; z < amount; z ++ ) {

							matrix.setPosition( offset - x, offset - y, offset - z );

							mesh.setMatrixAt( i, matrix );
							mesh.setColorAt( i, color.setHex( Math.random() * 0xffffff ) );

							i ++;

						}

					}

				}

				scene.add( mesh );

				//

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				document.body.appendChild( renderer.domElement );

				//

				const environment = new RoomEnvironment();
				const pmremGenerator = new THREE.PMREMGenerator( renderer );

				scene.environment = pmremGenerator.fromScene( environment ).texture;
				environment.dispose();

				//

				composer = new EffectComposer( renderer );

				renderPass = new RenderPass( scene, camera );
				renderPass.enabled = false;

				taaRenderPass = new TAARenderPass( scene, camera );

				outputPass = new OutputPass();

				composer.addPass( renderPass );
				composer.addPass( taaRenderPass );
				composer.addPass( outputPass );

				//

				controls = new OrbitControls( camera, renderer.domElement );
				controls.enableZoom = false;
				controls.enablePan = false;

				controls.addEventListener( 'change', () => ( needsUpdate = true ) );

				//

				const gui = new GUI();

				gui.add( params, 'alpha', 0, 1 ).onChange( onMaterialUpdate );
				gui.add( params, 'alphaHash' ).onChange( onMaterialUpdate );

				const taaFolder = gui.addFolder( 'Temporal Anti-Aliasing' );

				taaFolder.add( params, 'taa' ).name( 'enabled' ).onChange( () => {

					renderPass.enabled = ! params.taa;
					taaRenderPass.enabled = params.taa;

					sampleLevelCtrl.enable( params.taa );

					needsUpdate = true;

				} );

				const sampleLevelCtrl = taaFolder.add( params, 'sampleLevel', 0, 6, 1 ).onChange( () => ( needsUpdate = true ) );

				//

				stats = new Stats();
				document.body.appendChild( stats.dom );

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );
				composer.setSize( window.innerWidth, window.innerHeight );

				needsUpdate = true;

			}

			function onMaterialUpdate() {

				material.opacity = params.alpha;
				material.alphaHash = params.alphaHash;
				material.transparent = ! params.alphaHash;
				material.depthWrite = params.alphaHash;

				material.needsUpdate = true;
				needsUpdate = true;

			}

			function animate() {

				render();

				stats.update();

			}

			function render() {

				if ( needsUpdate ) {

					taaRenderPass.accumulate = false;
					taaRenderPass.sampleLevel = 0;

					needsUpdate = false;

				} else {

					taaRenderPass.accumulate = true;
					taaRenderPass.sampleLevel = params.sampleLevel;

				}

				composer.render();

			}

		</script>
	</body>
</html>
